2.4 Cell proliferation assay
Cell proliferation was detected using a Cell Counting Kit-8 (CCK-8;
Biosharp; Cat#BS350A). HUVECs and HDF cells were separately seeded
2×103/well in 96-well plates. The cells were allowed
to adhere for 12 h at 37 °C in 5% CO2. After 12 h, the
medium was removed and replaced with 100 μL of FGF2 or PEG-FGF2
conjugates for 24 h before addition of CCK-8 solution (10 μL) to each
sample. The absorbance was measured at 450 nm using a microplate reader
(Molecular Devices, USA). Cell proliferation assays were performed in
triplicate.